DENVER — Students and staff demanded answers Thursday nearly a month after officers went classroom by classroom at a largely minority high school in Denver and asked teenagers for their IDs as they looked for a suspect in a shooting.

Several students spoke at a school board meeting, saying the April 24 search made them feel targeted, disrespected and unsafe.

“We should not be treated like animals that have just run away from a shelter. We should be treated like humans, like students,” said Mary Jimenez, a 17-year-old junior at Rise Up Community School. “Because we are students of colour and students of low income, we get harassed and pushed around and we’re expected not to fight back.

“We need our respect and we need answers,” she said to loud applause.

Denver police said Thursday that they have launched an internal investigation,

“What happened should not have happened,” Denver Public Schools Superintendent Tom Boasberg said.

The search occurred at the small alternative charter school for students ages 16 through 20 who have dropped out of traditional schools or who are at risk of leaving school. Principal Lucas Ketzer said officers looked for the juvenile suspect over his objections, which he said caused students to feel unsafe and intimidated.

Police pushed a teacher away from her classroom after she said she wouldn’t allow them to enter without a warrant and pulled a gun on a teacher who went out a back door looking for students in an alley where they sometimes hang out, he said.

“I have heard the concerns from the community and independent monitor regarding the incident that occurred at the RiseUp Community School, and an administrative investigation was opened this morning to review the incident,” Department of Public Safety executive director Troy Riggs said, referring to the civilian oversight agency for Denver’s police and sheriff departments.

The principal questioned whether police would have conducted such a search at a school with more affluent students. He said his students commonly report feeling intimidated by police outside of school and that the search showed teachers working to gain their confidence cannot protect them from that.

“This just sets back all the work we’re trying to do because the trust is broken again,” Ketzer said.

He said he initially searched for the student at school April 24 and told police he was not there. School district security then intervened, allowing the officers to go inside.

Police said in a statement that they had confirmation from a school staffer that the suspect was there. Because of that and the “potentially dangerous circumstances,” police said they did not need a warrant.

Police said no guns were drawn inside the school but did not address Ketzer’s allegation about the teacher outside.

The principal said police told him they wanted to speak to a student potentially involved in a shooting in suburban Lakewood the night before but that officers did not mention any suspicion of him being armed. The juvenile suspect turned himself in a few days later and has been charged with attempted first-degree murder.

Student Marquise Tom, 20, said police approached him outside during lunch. He said police told him he looked like a suspect they were looking for and asked him for his ID.

Tom said he is friends with the suspect, who has lighter skin and fewer tattoos. Later, he said officers came into his classroom and asked a boy to take off his hat so they could look at his face.

“It just made me feel irritated and angry because I couldn’t focus and do my work,” he said.

The school district said its safety chief allowed the search because of the risk of an armed student at school but realizes it was traumatic.

“We look forward to working with our schools, community partners, and the Denver Police Department to ensure that our school-based policing practices preserve the safety and dignity of all involved,” the district said in a statement.

One expert in police training said making an arrest at school can be the right approach to take someone suspected of a violent crime into custody uneventfully.

In a school environment, though, officers have to follow procedures and be co-operative with school officials to minimize risk to everyone else, said Jon Shane, an associate professor at the John Jay College of Criminal Justice in New York.

“You have a contained environment and you know exactly where the suspect is,” said Shane, a former police captain in Newark, N.J. “You want to be able to expedite things, keep him from running away or getting outside the school and running off.”

An independent monitor will oversee the police investigation and civilian employees of the police’s conduct review office will review the results to see if any rules or policies were broken, Riggs’ spokeswoman, Daelene Mix, said. If there were, Riggs would ultimately be the one to decide whether any disciplinary action is warranted.